Played vs DyDo. Won in 8:20 first try and 7:41 second try. I think this could go faster too... DyDo seems to spend too much time messing about with factory modules and not enough time building tanks in the first two minutes, by which time, they have heavy MGs hardpoints right outside their base...

So, what else would you have the AI do this on this map?

I think the AI should rush the centre with trucks + tanks (mini-pod and heavy MG), build up lots of heavy MG hardpoints and MG bunkers around the centre, especially on the two resources nearest the player. AI might be vulnerable to a turtle player just building hardpoints at the bottom of each ramp and then building up morters and sensors though.
Also, the AI attacks the heavy MG hardpoints outside of your base. It should just go straight through and attack the base itself, factories, power centres etc. Those MG hardpoints waste time, tanks and power.

I played this last night in 2.3b11a, default AI. Won in 31 minutes, with no unit losses. I realize that my time is a lot slower than other peoples in this thread, but this was also only my second skirmish game ever, and the first on this map. I spent a bit of time having units explore in directions that were somewhat less than useful, and I still don't know the tech tree as well as I might. (I had to save in the middle to go look up the tech tree in the guide, because I was missing some upgrade that I was expecting). No losses I think means I am playing more (too?) conservatively with my units. By Per's description, the semperfi AI would have eaten me for lunch. If I play it again, though, I can definitely be a bit more aggressive about the early game.

I've been trying to get a video of this challenge in under 10 minutes so our good sir Daltx could post it on his YouTube channel. My first attempt was over 30 minutes. I've probably completed it 20 times since and finally I've achieved:

Video to follow.

My previous best was 10 minutes, which is partially to blame for the extremely low vid I made (made it solely to play was VirtualDubb as a video capture program, you will see I need to tweak it).

How I did it:

I used Heavy Machinegun, Cobra, Half-tracks.

Send your starting trucks to the farthest oil just outside the enemies base. Ignore the Scavengers and the oil. Order a total of 4 HMG hardpoints (2 on each side of the main ramp to the enemy's base). Meanwhile, order two trucks from each factory. With two trucks add the 3rd mod to one fac (and order to build hmg cobra half tracks) then build the 2nd and 3rd mod of the other fac, order hmg cobra. Set the waypoint of each factory behind the hmg hardpoints you have built. With 3 of your new trucks build a new power gen and mod while you order the 4th to demo def and structs you don't need (i.e., command relay, cyborg fac, etc) and order your 2 starting trucks to build the however many oil are free in the middle.

I did this with 6 oil total. Also, when the extra trucks are done building / demoing send them 1by1 to the corners of the map to look for oil barrels.

During this research the first 3 mg power up tech, and the first 2 tank armor tech. When you're able res automated manufacturing to get ROF tech.

Attack with about 9 units, push your way into the enemy base ignoring it's def, take out enemy tanks in your way but get your tanks behind it's factories a.s.a.p. Take out factories / borg in base, factory outside of base if your incoming tanks haven't already and:

Mission Successful

This is why some features aren't implemented: http://forums.wz2100.net/viewtopic.php?f=30&t=7490&view=unread#p87241

Send your starting trucks to the farthest oil just outside the enemies base. Ignore the Scavengers and the oil. Order a total of 4 HMG hardpoints (2 on each side of the main ramp to the enemy's base).

Am I wrong or are these low times now impossible? Using 2.3.5 RC4 with difficulty set to normal and the default AI, I get scavengers on my trucks one after another as soon as I send them up my own ramp to the high ground. (No possibility to scoot to the enemy's ramp and start the blockade with HMG hardpoints.) The best I can to to get across the highground with my trucks (while units build) is to build a MG tower not far from the top of my ramp, then another halfway, then another to cover me when I finally send three or four trucks to build some HMG hardpoints at the enemy's ramp. And even then I have to build a repair tower on my ramp to heal the trucks wounded by scavengers.

By this time The enemy seems to have gotten his act together and takes some work to defeat. 18-20min in all with HMG Cobra Tracks and another (closer) repair tower, in my case, but I'm no master.

I assume that for effigy and co above, that the scavengers stayed put if not disturbed. or?

EDIT: I've now got it down to 12 minutes. But can't manage less.
EDIT2: OK, 10:30, but that's it. You've got to at least build two HMG Hardpoints to keep the scavengers in check. And I can't get by without at least one repair tower (built near the top of the enemy's ramp). Also, I build 3 of the oil wells on the high ground: NW, SW, NE. To build on SE, you'd have to trounce the scavenger base nearby and that would take time.

Send your starting trucks to the farthest oil just outside the enemies base. Ignore the Scavengers and the oil. Order a total of 4 HMG hardpoints (2 on each side of the main ramp to the enemy's base).

Am I wrong or are these low times now impossible?

Hmmm, this is an old post I've been avoiding since first noticing it's an old post, some time ago, but according to the date of the post I would have used v2.3.0 to get that time. However, I can't come even close to that in the current so, so yeah, I'm guessing it's not possible due to balance changes and/or the AI has improved. I don't think 2.3.0 (2.3.2 IIRC) suffered the armor bug, but that'd be a convenient explanation.

Someone prove me wrong, please

This is why some features aren't implemented: http://forums.wz2100.net/viewtopic.php?f=30&t=7490&view=unread#p87241

I decided to try this challenge earlier today, but my fastest time so far was around 21 minutes, even though I did take some advice from other posters in this thread. (My game's version was 2.3.7, and the AI opponent was the default game AI by the way.)

I started things off by ordering all 3 of my starting factories to produce both Trucks and Combat Engineers (around 2 trucks from my T1 factory, 3 trucks from my T2 factory, and 3 engineers from my cyborg factory at 1st) so that I could quickly take the central plateau. Once those were done, I then started producing a few Commander Viper Wheels (You start with a command relay center by the way.) to bolster my forces and reduce the amount of micromanagement that I'd otherwise need to control my forces (by automatically telling my units to go for repairs as needed, then return to battle once fully repaired, and by automatically assigning units that were produced in different factories towards these commanders). Afterwards, I began to pump out endless amounts of Medium Cannon Cobra Wheels (to keep their speed high while mounting the Medium Cannons), Heavy Gunners, Grenadiers, and Cyborg Flamers, sometimes building some engineers to replace the ones that I lost. (I did lose a few trucks and engineers as they were coming under fire from scavengers mostly while I was building my initial defenses on those chokepoints.)

Initially, I sent my trucks and engineers to build a number of defenses, starting with a Heavy Machinegun Hardpoint and a Flamer Bunker on the western chokepoint (I'll call this position B) to keep the western scavengers away, then blocking off the northern chokepoint (I'll call this position A) with Light Cannon Hardpoints while also placing a couple Repair Facilities nearby (so that a large army can get repaired more quickly), then placing another Heavy Machinegun Hardpoint and Flamer Bunker on the eastern chokepoint (I'll call this position C) to keep the eastern scavengers away. Once all this was done, I then built a number of mortar pits near the northeastern oil derrick on the central plateau, and a couple sensor towers: 1 at position A (for defense) and the other at the northeasternmost edge of the plateau (for bombarding the opponent's oil derricks, as well as the scavengers' eastern oil derrick). I also built a couple Cyborg Factories on the plateau so that I could more cyborgs for assaulting the enemy base.

While I did all of this, I kept one of my trucks close to my starting base to demolish all of my base defenses there (for extra power. Besides, I didn't need them), then to build a power plant and a couple research labs (and upgrade them) afterwards. I also built oil derricks as positions were being secured by my new defenses. Later on, I built an extra power plant as I took over both of the scavengers' 2 oil derricks.

As far as research was concerned, I started things off by researching Improved Hardcrete (to help keep my defenses alive) and HEAT Cannon Shells (as I was going to use Cannons, including Medium Cannons, for both offense and defense). Once I researched Medium Cannons, I then researched Mortar Pits so that I could build those Mortar Pits at the NE oil derrick as I mentioned before. From there, I decided to focus on improving the firepower of Cannons, Mortars, and Flamers, as well as improving both vehicle and cyborg armor, throwing in the occasional Synaptic Link Data Analysis or Factory Upgrade from time to time.

Note that I had my units set to fire at long range (except for flamers, in which I set them to close in at short range) so that they can keep out of range of enemy base defenses. I also alternated between having my units retreat for repairs at medium and heavy damage so that I can keep losses to a minimum.

As for how I completed my objective, I decided to do this cautiously. My opponent had built a couple machinegun bunkers near the entrance towards its base, as well as numerous cyborg flamers and cyborg lancers to protect its base. That, and there were also all of those pre-built machinegun hardpoints and towers that needed to be dealt with before I could safely storm the main base.

By the way, this challenge seems to be somewhat easier on master. The AI just doesn't build so many big structures around. I could get 7:20 without problems, but i was hardly at my best.

By the way, i tend to include a few mortar cyborgs into the effigy's hmg cobra mix; they're rather good in killing wheeled trucks/tanks, borgs and buildings, and that's a good early pressure. Still, they die too easily against enemy defenses, so they're useless on the final phase, so don't make more than 5 of them.